During crisis situations, Twitter can be a useful resource for people seeking information from witnesses or officials about what transpired and what might happen next. But the social media platform can also be a breeding ground for rampant misinformation during breaking news events. Tuesday’s shooting at YouTube’s headquarters was a case in point.

As the shooting unfolded at YouTube’s campus in San Bruno, California, hoaxes and other misinformation began spreading on Twitter. Various people were erroneously identified as the shooter, including YouTube personality Matt Jarbo and comedian Sam Hyde. Hyde is often targeted by hoaxers in the aftermath of shootings.

So far I've seen several hoaxes purporting to show the shooter is: Sam Hyde, "a woman in a headscarf," Anita Sarkeesian, and Hillary Clinton.

In the minutes after the shooting, a verified Twitter account belonging to Vadim Lavrusik, a product manager at YouTube, was hacked by an unknown troll who began posting tweets about the attack, including one that read “PLEASE HELP ME FIND MY FRIEND I LOST HIM IN THE SHOOTING.”

Twitter CEO Jack Dorsey was alerted to the hack and said his team was “on it.”